In addition to standard lights, what light do airships carry?

Airships are equipped with a white nose-light in addition to their standard illumination. This white light is generally used to enhance visibility and increase safety during flight, particularly in low-light conditions. The white nose-light assists other pilots and air traffic controllers in identifying the orientation and direction of the airship, helping to prevent potential mid-air collisions.

The other options, while they are types of navigation lights used on various aircraft, do not specifically define the unique lighting equipment that airships carry. For instance, red and green navigation lights are typically used to indicate the aircraft's left and right sides respectively, primarily for fixed-wing aircraft and helicopters. A flashing white light is not standard for airships, which rely on the white nose-light for visibility. Thus, the presence of the white nose-light is what distinguishes airships and makes it the correct answer in this context.